Xerographic reproportioning method and apparatus

ABSTRACT

A method and apparatus is shown for reproportioning a xerographic powder image before transferring it from a photoconductive surface to a support material.

United States Patent [1 1 Perez I XEROGRAPHIC REPROPORTIONING METHOD AND APPARATUS 75 Inventor: John M. Perez, San Jose, Calif.

[73] Assignee: Lockheed Missiles & Space Company, Inc., Sunnyvale, Calif.

22 Filed: Oct. 10,1972

211 App]. No.1 296,145

[52] US. Cl 355/3, 355/9, 95/4.5 [51] Int. Cl G03g 15/14 [58] Field of Search 355/3, 9, 17; 95/4.5 J

[56] References Cited UNITED STATES PATENTS 2,177,539 10/1939 Spielvogel 95/4.5 J

[ Mar. 26, 1974 6/1966 Home 95/4.5 J 2/1924 Savage 95/4.5 J

Primary Examiner-John M. l-loran' Attorney, Agent, or Firm-Billy G Corber 5 7 ABSTRACT A method and apparatus is shown for reproportioning a xerographic powder image before transferring it from a photoconductive surface to a support material.

2 Claims, 4 Drawing Figures PAIENIEBIIARZBIHH 3.799.667

saw 1 nr 2 THE POWDER IMAGE IMAGE TO PAPER MEMBER HEATING THE PAPER MEMBER TRANSFERRING IMAGE TO INTERMEDIATE MEMBER PRESSING PAPER MEMBER ONTO INTERMEDIATE MEMBER DEVELOPING PLATE TRANSFERRING IMAGE TO TRACTILE MEMBER REPROPORTIONING TRANSFERRING FIG. 1

FIG. 2

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PATENTEDMARZS 1974 SHLU 2 [IF 2 FIG. 3

XEROGRAPHIC REPROPORTIONING METHOD AND APPARATUS BACKGROUND OF THE INVENTION This invention relates to a method for transferring a xerographic powder image from a xerographic plate to support material, and, in particular, to method for transferring the powder image to an intermediate member, reproportioning the image, and then transferring the image to a paper member.

More specifically, the invention relates to an improved method for transferring and reproportioning a xerographic powder image before transferring it from a photoconductive surface to the support material. In the conventional process of xerography, as shown by U.S. Pat. No. 3,591,276, a plate, comprising a conductive backing upon which is placed a photoconductive insulating material, is charged uniformly and the conductive surface is then exposed to a light image. The

I charge on the drum is'dissipated in the exposed areas,

thusforming a latent electrostatic image of the copy to be reproduced. The latent image is then exposed to pig ment resins, which are called toners which are electrostatically .attraetedto the latent image. A support material, usually paper, is then brought into, contact with the plate and the powder image is transferred from the plate surface to the paper member.

.When making ar t layouts, it is sometimes necessary to reproportion a piece of art work and this cannot be done with a conventional xerographic process. There have been other reproportion devices proposed but none are compatible with the xerographic process. Someprior devices project an image on a highly polished flexible sheet of material. The contour of the flexible sheet can be changed to distort the image to achieve artistic effects and facilitate nonuniform reduction or enlargement. See U.S. Pat. No. 1,457,209 and 2,565,446. Other reproportioning devices use a photographic process for distorting linotype so that all the letters are altered equally in any one direction. See U.S. Pat. No. 2,314,272. A photographic device for distortinglinotype or other pattern in a non-uniform manner also is known. See U.S. Pat. No. 3,374,724. A third photographic device for reproportioningan image utilizes apair of rotating cylinders. The original is attached to one rotating cylinder and the sensitive film'is attached to the other. The image is projected from one cylinder to the other through a linear aperture mounted between the cylinders and mounted on their longitudinal axis. See U.S. Pat. No. 3,445,161. Another reproportioning device utilizing a band for radiating energy comprises a device in which the document to be copied is moved in one direction transverse to the band of radiant energy and a radiation sensitive copy is simultaneously moved in the opposite direction from the document. See U.S. Pat. No. 3,204,543. None of the above reproportioning devices are compatible with the xerographic process and for one reason or another they have limitations and have not found commercial success.

The present method and apparatus allows the use of the xerographic process for reproportioning art work. After the latent image has been transferred to the support material, the support material is placed face-down on the flexible surface and the latent image is transferred to the flexible surface. The flexible surface can then be expanded by stretching (or contracted by removing a pre-stretch condition). A clear, intermediate number can then be placed on the flexible surface and the latent image is then transferred to it. The clear support member can then be heated to fix the latent image thereon or a paper member may be brought into contact with the transparent member and the image transferred to the paper member.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 isv an enlarged cross-sectional view along lines AA of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the process for reproportioning comprises the steps as follows:

a charging station 1 at which a uniform electrostatic charge is deposited on the plate;

an exposing station 2 at which a light image of the copy to be reproduced is projected onto the plate to dissipate the charge and thus exposing areas thereon so as to form a latent electrostatic image of the copy to be reproduced;

developing station 3 at which point charge toner particles are brought into close proximity to the photoconductive surface and attracted to the charged areas; thereby developing the latent image;

a first transferring station 4 where the image is transferred to the traetile member;

a reproportioning station 5 where the image is expanded in one direction until-the desired expansion has been obtained;

a second transferring station 6 where the image is transferred from the traetile member to the final support material such as paper; and

the heating station 7 where the image is permanently affixed to the final support member by heating.

In the alternative system of FIG. 2 it may be seen that a transferring station 10 and pressing station 11 is connected at A in FIG. 1 in place of the second transferring station 6 and heating station 7. In this embodiment, after the reproportioning'station 5 is an intermediate transferring station 10 where a clear piece of contact film is placed sticky side down on the image after it has been reproportioned. This transfers the image to .the film and at the same time clears the surface of the tractile member. At the final transfer station 11, the film is placed sticky side down on a piece of paper. The latent image is then sealed between the paper and the contract film and is visible through the clear contact film. Obviously, if a more permanent copy or a darker copy is desired, this can be obtained by processing the copy through a conventional xerographic reproducer.

FIG. 3shows a preferredform of the traetile device 20 which includes a traetile member 21, which can be surgical rubber or any other well known means that is tractile. One end of tractile member 21 is rigidly affixed to the frame 22 by first metal clamp 23 and screws 24 or any other well known device. Drum 25 which includes a worm gear drive 26 having a crank 27 is journaled to the end of the frame 22 opposite from the first metal clamp 23. The other end of the tractile member 21 is rigidly affixed to the drum 25 by second metal clamp 28 and screws 29 or any other well known means. A scale 30 is mounted on the side of the frame FIG. 4 is a cross-sectional view taken along lines 4-4 of FIG. 3. This shows plate 31 which has previously been exposed and then developed so that the toner 32 is electostatically attracted to it. The plate, with the side containing the toner facing down is pressed against the tractile member 21 so that the toner is transferred to the tractile member. Plate 31 is then removed and crank 27 can be operated to elongate the tractile member and the latent image carrying toner. Drum 25 and metal clamp 23 retain the tractile member 21 taut so that the tractile member 21 and frame 22 are separated by gap 35 to allow the tractile member 21 to be uniformly elongated.

It may be seen that there has been described herein a novel and improved reproportioning method and device. While the description herein is presently considered to be preferred, it is contemplated that further modifications and improvements within the purview of those skilled in the art may be made herein. The following claims are intended to cover all such variations and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. In the process of xerography wherein an electrostatically charged xerographic plate is exposed to a projected light image to form an electrostatic latent image on the plate corresponding to the projected image and the plate is developed with heat fusible toner particles attracted to the latent image to form a xerographic powder image corresponding to the projected image, the method of transferring and reproportioning the powder image to a paper member comprising:

pressing a tractile member into intimate contact with the powder bearing xerographic plate whereby the powder image is transferred to the tractile member;

removing the image-bearing tractile member from the xerographic plate;

lenthening the image bearing tractile member whereby the image is reproportioned;

pressing a preheated member into intimate contact with the image bearing tractile member whereby the reproportioned powder image is transferred to the paper member; and

heating the image bearing paper to fix the image thereon.

2. In the process of xerography wherein an electrostatically charged xerographic plate is exposed to a projected light image to form an electrostatic latent image on the plate corresponding to the projected image and the plate is developed with heat fusible toner particles attracted to the latent image to form a xerographic powder image corresponding to the projected image, the method of transferring, and reproportioning the powder image to a paper member comprising:

pressing a tractial member into intimate contact with the powder bearing xerographic plate whereby the powder image is transferred to the tractile member;

removing the image bearing tractile member from the xerographie plate;

lengthening the image bearing tractile member whereby the image is reproportioned;

pressing a stickey-faced substantially transparent intermediate member into intimate contact with the image bearing tractile member whereby the reproportioned powder image is transferred to the intermediate member, and

pressing a paper member into intimate contact with the stickey faced side of said image bearing intermediate member whereby the image is visible through the intermediate member against the background of the paper member. 

1. In the process of xerography wherein an electrostatically charged xerographic plate is exposed to a projected light image to form an electrostatic latent image on the plate corresponding to the projected image and the plate is developed with heat fusible toner particles attracted to the latent image to form a xerographic powder image corresponding to the projected image, the method of transferring and reproportioning the powder image to a paper member comprising: pressing a tractile member into intimate contact with the powder bearing xerographic plate whereby the powder image is transferred to the tractile member; removing the image-bearing tractile member from the xerographic plate; lenthening the image bearing tractile member whereby the image is reproportioned; pressing a preheated member into intimate contact with the image bearing tractile member whereby the reproportioned powder image is transferred to the paper member; and heating the image bearing paper to fix the image thereon.
 2. In the process of xerography wherein an electrostatically charged xerographic plate is exposed to a projected light image to form an electrostatic latent image on the plate corresponding to the projected image and the plate is developed with heat fusible toner particles attracted to the latent image to form a xerographic powder image corresponding to the projected image, the method of transferring and reproportioning the powder image to a paper member comprising: pressing a tractial member into intimate contact with the powder bearing xerographic plate whereby the powder image is transferred to the tractile member; removing the image bearing tractile member from the xerographic plate; lengthening the image bearing tractile member whereby the image is reproportioned; pressing a stickey-faced substantially transparent intermediate member into intimate contact with the image bearing tractile member whereby the reproportioned powder image is transferred to the intermediate member, and pressing a paper member into intimate contact with the stickey faced side of said image bearing intermediate member whereby the image is visible through the intermediate member against the background of the paper member. 